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Biomedical subjects

David L Cochran

Publications and source records attributed to David L Cochran.

At least 19 recordsLinked to original sources
PubMed2007

In vitro effects of enamel matrix derivative on microvascular cells.

BACKGROUND: Periodontal regeneration requires a coordinated series of events that includes not only the recruitment of periodontal ligament (PDL)-specific cells, but vascular cells as well. The mechanisms of action of enamel matrix derivative (EMD) are poorly understood, and its effects on vascular cells are unknown. The objective of this study was to examine the extent to which EMD affects angiogenesis and PDL cell recruitment. METHODS: The effects of EMD on human microvascular endothelial cells (HMVECs) were determined by examining proliferation, chemotaxis, angiogenesis, and migration. Proliferation was determined using water-soluble tetrazolium salt (WST)-1 reagent. Chemotaxis was determined using microporous-culture well inserts. Angiogenesis was assessed on plates containing matrigel. The effects of HMVECs on the migration of PDL cells were assessed by evaluating PDL cell outgrowth from collagen gels cultured in the presence of HMVECs on fibrin matrix and surrounded by fibronectin-containing fibrin clots at 24 hours. Effects of EMD on PDL expression of vascular endothelial cell (VEGF) types (A, B, C, and D) and isoforms were determined using reverse transcription-polymerase chain reaction (RT-PCR). Production of VEGF, platelet-derived growth factor (PDGF)-AA, PDGF-BB, PDGF-AB, and transforming growth factor (TGF)-beta1 by EMD-stimulated PDL cells was assessed quantitatively in conditioned media using specific enzyme-linked immunosorbent assays (ELISAs). RESULTS: EMD at concentrations <50 microg/ml resulted in significant (P <0.05) stimulation of HMVEC proliferation. Compared to baseline, EMD also stimulated a 100% increase in HMVEC chemotaxis when PDL cells were present (P <0.05). All doses of EMD tested (25, 50, and 100 microg/ml) increased angiogenesis in vitro. HMVECs, in combination with EMD at a concentration of 100 microg/ml, stimulated a 750% increase in migration of PDL cells from collagen gels into fibrin clots compared to controls when neither was present. RT-PCR results indicated that PDL cells expressed VEGF-A, -B, and -C and multiple isoforms of VEGF-A, including VEGF(121), VEGF(165), and VEGF(189), whether or not EMD was present in the culture media. ELISAs determined a 400% increase in VEGF concentration by PDL C cells in EMD-stimulated conditioned media and a similar increase in TGF-beta(1)-stimulated media. CONCLUSIONS: It is likely that EMD stimulates angiogenesis directly by stimulating endothelial cells and indirectly by stimulating the production of angiogenic factors (VEGF) by PDL cells. Importantly, the data are consistent with the concept that EMD enhances bidirectional communication between HMVEC and PDL cells during angiogenesis associated with healing.

Cell Communication↗
PubMed2006

Integrin beta1 silencing in osteoblasts alters substrate-dependent responses to 1,25-dihydroxy vitamin D3.

Surface microroughness increases osteoblast differentiation and enhances responses of osteoblasts to 1,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3]. The observations that beta1 integrin expression is increased in osteoblasts grown on Ti substrates with rough microarchitecture, and that it is regulated by 1alpha,25(OH)2D3 in a surface-dependent manner, suggest that beta1 may play a role in mediating osteoblast response. To test this hypothesis, we silenced beta1 expression in MG63 human osteoblast-like cells using small interfering RNA (siRNA) and examined the responses of the beta1-silenced osteoblasts to surface microtopography and 1alpha,25(OH)2D3. To better understand the role of beta1, MG63 cells were also treated with two different monoclonal antibodies to human beta1 to block ligand binding. beta1-silenced MG63 cells grown on a tissue culture plastic had reduced alkaline phosphatase activity and levels of osteocalcin, transforming growth factor beta1, prostaglandin E2, and osteoprotegerin in comparison with control cells. Moreover, beta1-silencing inhibited the effects of surface roughness on these parameters and partially inhibited effects of 1alpha,25(OH)2D3. Anti beta1 antibody AIIB2 had no significant effect on cell number and osteocalcin, but decreased alkaline phosphatase; MAB2253Z caused dose-dependent decreases in cell number and alkaline phosphatase and an increase in osteocalcin. Effects of 1alpha,25(OH)2D3 on cell number and alkaline phosphatase were reduced and effects on osteocalcin were increased. These findings indicate that beta1 plays a major and complex role in osteoblastic differentiation modulated by either surface microarchitecture or 1alpha,25(OH)2D3. The results also show that beta1 mediates, in part, the synergistic effects of surface roughness and 1alpha,25(OH)2D3.

Animals↗
PubMed2006

Consequences of implant design.

The use of dental implants to replace missing teeth is becoming a preferred alternative for restorative dentists and their patients. There are two general surgical approaches for the placement and restoration of missing teeth using endosseous dental implants. One approach places the top of the implant at the alveolar crest and the mucosa is sutured over the implant. An alternative approach places the coronal aspect of the implant coronal to the alveolar crest and the mucosa is sutured around the transmucosal aspect of the implant. This article reviews one-piece and two-piece implants as well as biologic implications of submerged and non-submerged surgical techniques for placing implants.

Alveolar Process↗
PubMed2006

Application of periodontal tissue engineering using enamel matrix derivative and a human fibroblast-derived dermal substitute to stimulate periodontal wound healing in Class III furcation defects.

BACKGROUND: Enamel matrix derivative (EMD) has been shown to promote several aspects of periodontal regeneration in vitro and in vivo. Recently, a bioengineered tissue (DG) was developed to promote wound healing of chronic skin ulcers. This pilot study sought to assess the effects of EMD and DG, alone or in combination, on periodontal wound healing in surgically created Class III furcation defects. METHODS: Six female baboons received bilateral ostectomy of approximately 10 mm around the first and second mandibular molars to achieve Class III, subclass C furcation defects. Wire ligatures and cotton pellets were left in place for 2 months to maintain the depth of the defects and promote plaque accumulation. Each furcally involved molar was then assigned to one of four treatments: open flap debridement (OFD), OFD plus EMD, OFD plus DG, or OFD plus DG and EMD. This resulted in six total sites per treatment group. Seven months after defect creation and 5 months after treatment, and after no oral hygiene, tissue blocks of the mandible were taken for blinded histometric analysis to assess parameters of periodontal regeneration adjacent to furcal root surfaces and from the mid-furcal aspect (i.e., new bone, new connective tissue attachment, new epithelial attachment, and new cementum formation). RESULTS: Histometric analysis demonstrated differential regenerative responses with respect to treatment within each animal. However, statistically significant differences between treatments from all six animals were not observed (P >0.20, mixed-model analysis of variance). EMD-treated sites presented mildly positive regenerative results and no negative responses. Both DG only and combination therapy demonstrated similar or less than positive responses relative to OFD controls. CONCLUSION: The descriptive analysis may suggest a positive effect of enamel matrix proteins and a negative effect of DG used alone or in combination with enamel matrix proteins on the regeneration of Class III furcation defects in baboons.

Animals↗
PubMed2006

Human periodontal fibroblast response to enamel matrix derivative, amelogenin, and platelet-derived growth factor-BB.

BACKGROUND: The ideal goal of clinical therapy in periodontal defects is regeneration of all lost structures. For regeneration to occur, cell proliferation, migration, and extracellular matrix synthesis are prerequisites. Attempts at regeneration of periodontal defects by guided tissue regeneration using bone grafts and membranes have not always yielded predictable results. Recently, attempts at engineering the defects using various materials have shown promising results. Two such approaches have been used to regenerate periodontal defects, one using extracellular matrix such as enamel matrix proteins and the other using growth factors. However, to our knowledge, no study has looked at combining these two approaches to achieve potentially even greater regeneration. METHODS: Primary human periodontal ligament (PDL) fibroblasts were explanted, and alkaline phosphatase (ALK PHOS) activity was determined. Phenotypically different cell lines were incubated for 1, 3, 6, and 10 days in 0.2% fetal bovine serum (FBS) media containing different concentrations of either enamel matrix derivative (EMD), amelogenin, platelet-derived growth factor-BB (PDGF-BB), EMD+PDGF-BB, or amelogenin+PDGF-BB. A culture of 0.2% FBS alone served as a negative control, and a culture of 10% FBS served as a positive control. Cell proliferation was measured using a Coulter counter to determine the cell number. The effects on a wound-fill model were evaluated by scraping a 3-mm wide cell-free zone in PDL monolayers across the diameter of the tissue-culture plate and determining PDL cell migration into the cell-free zone using computer assisted histomorphometry. RESULTS: Compared to the control, only EMD+PDGF-BB significantly increased PDL cell proliferation in an ALK PHOS (-) cell line (P<0.001), and EMD alone, EMD+PDGF-BB, and amelogenin+PDGF-BB significantly increased PDL cell proliferation in an ALK PHOS (+) cell line (P<0.001) with EMD+PDGF-BB showing a trend for greater proliferation than either PDGF or EMD alone. Individually, EMD and amelogenin had no significant effect on PDL cell proliferation. In the wound-fill experiment, all factors and their combinations except amelogenin significantly enhanced cell migration compared to the control (P<0.05) at the wound edge. In addition, EMD+PDGF-BB had additive effects on the ALK PHOS (-) cell line at the wound edge. At the center of the wound, neither EMD nor amelogenin had a significant wound-fill effect. However, the combination of EMD+PDGF-BB additively increased wound fill for both ALK PHOS (+) and ALK PHOS (-) cells. CONCLUSIONS: The combination of EMD and PDGF-BB produces greater proliferative and wound-fill effects on PDL cells than each by themselves. If these combined effects can be translated clinically, one may see greater regeneration in periodontal defects with this combination. However, amelogenin does not have significant effects on PDL cell proliferation or migration by itself. This may suggest that either another enamel matrix component in EMD may be responsible for some of its clinical effects, or that amelogenin alone may not trigger the regenerative potential of periodontal tissues and that it requires a combined interaction with other enamel matrix components of EMD to direct the regenerative process.

Adult↗
PubMed2006

Effects of enamel matrix derivative on bone-related mRNA expression in human periodontal ligament cells in vitro.

BACKGROUND: Enamel matrix derivative (EMD) has demonstrated the potential to stimulate periodontal regeneration with mineralized tissue formation. Molecular regulators of bone metabolism include osteoprotegrin (OPG), receptor activator of nuclear factor kappa B ligand (RANKL), cyclooxygenase 2 (COX2), and core binding factor alpha 1 (Cbfa1). The role of these regulatory molecules within the context of EMD stimulation of mineralized tissue formation is unknown. Therefore, the purpose of this investigation was to explore the effects of EMD on these bone-related molecules in human periodontal ligament (PDL) cells. METHODS: Human PDL-cell cultures were treated with EMD (5 to 100 microg/ml) for 24 hours. Total RNA was isolated using phenolchloroform, and reverse transcription-polymerase chain reaction (RT-PCR) was performed using primers specific for OPG, RANKL, COX2, Cbfa1, and aldolase, with amplification in the exponential range for each molecule studied. RESULTS: The results of this study show that there is a significant (P <0.05) increase in COX2 mRNA levels with EMD treatment, and no effects were noted on mRNA levels for Cbfa1. RANKL mRNA levels were significantly decreased (P <0.01) up to 50% with EMD treatment > or =25 microg/ml. OPG levels showed minimal effects with EMD treatment. However, the RANKL/OPG ratio showed a 40% to 55% reduction with EMD >or =25 microg/ml. CONCLUSION: This study supports a role for EMD stimulation of mineralized tissue formation consistent with periodontal regeneration by modulating regulatory molecules critical to bone metabolism at the RNA level.

Adolescent↗
PubMed2006

The effect of rhBMP-2 around endosseous implants with and without membranes in the canine model.

BACKGROUND: Bone morphogenetic protein (BMP) is a potent differentiating agent for cells of the osteoblastic lineage. It has been used in the oral cavity under a variety of indications and with different carriers. However, the optimal carrier for each indication is not known. This study examined a synthetic bioabsorbable carrier for BMP used in osseous defects around dental implants in the canine mandible. METHODS: Twelve canines had their mandibular four premolars and first molar teeth extracted bilaterally. After 5 months, four implants were placed with standardized circumferential defects around the coronal 4 mm of each implant. One-half of the defects received a polylactide/glycolide (PLGA) polymer carrier with or without recombinant human BMP-2 (rhBMP-2), and the other half received a collagen carrier with or without rhBMP-2. Additionally, one-half of the implants were covered with a non-resorbable (expanded polytetrafluoroethylene [ePTFE]) membrane to exclude soft tissues. Animals were sacrificed either 4 or 12 weeks later. Histomorphometric analysis included the percentage of new bone contact with the implant, the area of new bone, and the percentage of defect fill. This article describes results with the PLGA carrier. RESULTS: All implants demonstrated clinical and radiographic success with the amount of new bone formed dependent on the time and presence/absence of rhBMP-2 and presence/absence of a membrane. The percentage of bone-to-implant contact was greater with rhBMP-2, and after 12 weeks of healing, there was approximately one-third of the implant contacting bone in the defect site. After 4 weeks, the presence of a membrane appeared to slow new bone area formation. The percentage of fill in membrane-treated sites with rhBMP-2 rose from 24% fill to 42% after 4 and 12 weeks, respectively. Without rhBMP-2, the percentage of fill was 14% rising to 36% fill, respectively. CONCLUSIONS: After 4 weeks, the rhBMP-2-treated sites had a significantly higher percentage of contact, more new bone area, and higher percentage of defect fill than the sites without rhBMP-2. After 12 weeks, there was no significant difference in sites with or without rhBMP-2 regarding percentage of contact, new bone area, or percentage of defect fill. In regard to these three outcomes, comparing the results with this carrier to the results reported earlier with a collagen carrier in this study, only the area of new bone was significantly different with the collagen carrier resulting in greater bone than the PLGA carrier. Thus, the PLGA carrier for rhBMP-2 significantly stimulated bone formation around dental implants in this model after 1 month but not after 3 months of healing. The use of this growth factor and carrier combination appears to stimulate early bone healing events around the implants but not quite to the same degree as a collagen carrier.

Absorbable Implants↗
PubMed2005

The use of guided tissue regeneration principles in endodontic surgery for induced chronic periodontic-endodontic lesions: a clinical, radiographic, and histologic evaluation.

BACKGROUND: Chronic periodontic-endodontic lesions are not uncommon in clinical practice and their regenerative capacity has long been questioned. However, there are no published studies investigating the application of guided tissue regeneration techniques in combination with endodontic surgery using an induced perio-endo defect model. This study evaluated the clinical, radiographic, and histologic outcomes of three surgical procedures used to treat induced perio-endo lesions. METHODS: Pulpal necrosis was induced in foxhounds along with surgical removal of radicular buccal bone. After 4 weeks, chronic lesions were clinically and radiographically assessed. Treatment surgery consisted of apicoectomy, root canal instrumentation, and retrofilling with mineral trioxide aggregate. Teeth were then assigned to one of the following treatment groups: open flap debridement only (OFD), OFD with bioabsorbable porcine-derived collagen membrane (BG), or OFD with BG and anorganic bovine bone matrix (BO/BG). Clinical parameters and standardized radiographs were assessed at defect creation; treatment surgery; and at 1, 2, 4, and 6 months. Animals were sacrificed at 6 months and specimens prepared for histometric analysis. RESULTS: Clinical and radiographic conditions improved during the study period. Mean epithelial attachment was similar between all groups. Mean connective tissue attachment for groups OFD, BG, and BO/BG was 3.79 mm, 2.63 mm, and 1.75 mm, respectively, and mean radicular bone height was 2.16 mm, 3.24 mm, and 3.45 mm, respectively. Statistically significant increases in the amount of new cementum were observed in groups BG and BO/BG when compared with OFD (P <0.05). CONCLUSIONS: Treatment of combined induced perio-endo lesions using bioabsorbable collagen membranes alone or in combination with anorganic bovine bone matrix resulted in increased amounts of bone, periodontal ligament, and significant increases in the amount of new cementum when compared to open flap debridement in a canine model.

Absorbable Implants↗
PubMed2005

Evaluation of demineralized bone matrix paste and putty in periodontal intraosseous defects.

BACKGROUND: Demineralized bone matrix (DBX) paste and putty are particulate demineralized bone matrices in a 2% or 4% hyaluronate carrier, respectively. The purpose of this study was to determine the effectiveness of DBX paste and putty compared to demineralized freeze-dried bone allograft (DFDBA) in the treatment of human intraosseous periodontal defects. METHODS: Sixty systemically healthy individuals between the ages of 31 and 71 years with at least one intraosseous periodontal defect of > or = 3 mm in depth and radiographic evidence of at least 40% to 50% vertical bone loss were accrued. Following initial non-surgical periodontal therapy, sites were randomly selected to receive either DBX paste, DBX putty, or DFDBA (control). Baseline and 6-month reentry soft and hard tissue parameter measurements were made by calibrated examiners. Data were analyzed within and between groups utilizing analysis of variance (ANOVA) and paired and unpaired Student t tests. RESULTS: Probing depth reductions were significantly improved in all treatment groups with DFDBA, DBX paste, and putty patients demonstrating 2.8 mm, 3.6 mm, and 2.3 mm, respectively. Attachment level gains were significantly improved from baseline for all treatment groups with DFDBA, DBX paste, and putty, respectively, demonstrating 2.4 mm, 2.9 mm, and 1.6 mm. Bone fill was similar between all groups with DBX paste, putty, and DFDBA control groups demonstrating 2.0 mm, 2.4 mm, and 2.2 mm, respectively. All groups yielded significant improvements in percent bone fill with DFDBA, DBX paste and putty, respectively, achieving 37%, 42.1%, and 50% with no significant differences between the groups. CONCLUSION: In summary, demineralized bone matrix paste, demineralized bone matrix putty, and demineralized freeze-dried bone allograft all demonstrated similar favorable improvements in soft and hard tissue parameters in the treatment of human intraosseous defects.

Adult↗
PubMed2005

Crestal bone changes around titanium implants. Part I: A retrospective radiographic evaluation in humans comparing two non-submerged implant designs with different machined collar lengths.

BACKGROUND: Experimental studies demonstrated that peri-implant crestal hard and soft tissues are significantly influenced in their apico-coronal position by the rough/smooth implant border as well as the microgap/ interface between implant and abutment/restoration. The aim of this study was to evaluate radiographically the crestal bone level changes around two types of implants, one with a 2.8 mm smooth machined coronal length and the other with 1.8 mm collar. METHODS: In 68 patients, a total of 201 non-submerged titanium implants (101 with a 1.8 mm, 100 with a 2.8 mm long smooth coronal collar) were placed with their rough/smooth implant border at the bone crest level. From the day of surgery up until 3 years after implant placement crestal bone levels were analyzed digitally using standardized radiographs. RESULTS: Bone remodeling was most pronounced during the unloaded, initial healing phase and did not significantly differ between the two types of implants over the entire observation period (P >0.20). Crestal bone loss for implants placed in patients with poor oral hygiene was significantly higher than in patients with adequate or good plaque control (P <0.005). Furthermore, a tendency for additional crestal bone loss was detected in the group of patients who had been diagnosed with aggressive periodontitis prior to implant placement (P = 0.058). In both types of implants, sand-blasted, large grit, acid-etched (SLA) surfaced implants tended to have slightly less crestal bone loss compared to titanium plasma-sprayed (TPS) surfaced implants, but the difference was not significant (P >0.30). CONCLUSION: The implant design with the shorter smooth coronal collar had no additional bone loss and may help to reduce the risk of an exposed metal implant margin in areas of esthetic concern.

Adult↗
PubMed2005

Platelet-derived growth factor inhibits demineralized bone matrix-induced intramuscular cartilage and bone formation. A study of immunocompromised mice.

BACKGROUND: Platelet-derived growth factor (PDGF) has been proposed as a therapeutic agent to promote bone-healing. The purpose of this study was to examine the effect of PDGF on the ability of human demineralized bone matrix to induce bone formation in a nude-mouse muscle-implantation model. We also examined whether platelet-rich plasma, which contains PDGF, also modulates osteoinduction in this model. METHODS: Human demineralized bone matrix, previously shown to be osteoinductive in the calf muscles of nude mice, was mixed with PDGF-BB (0, 0.1, 1, and 10 microg/10 mg of demineralized bone matrix) and was implanted bilaterally in the calf muscles of immunocompromised (nu/nu) mice (six mice in each group). Heat-inactivated demineralized bone matrix was used as a control. Tissue was harvested at fourteen, twenty-eight, and fifty-six days after implantation. Platelet-rich plasma was prepared from the blood of a healthy donor with use of the Harvest PRP preparation device, activated with thrombin, and mixed with active and inactive demineralized bone matrix. Fifty-six days post-implantation, tissues were harvested. Osteoinduction was assessed with use of a qualitative scoring system and with quantitative histomorphometry. RESULTS: Cartilage was present at fourteen days in all tissues that had received an implant, but the amount decreased as the PDGF concentration increased. PDGF reduced bone formation at twenty-eight days in a dose-dependent manner. This inhibitory effect was resolved by fifty-six days, except in tissues in which demineralized bone matrix and 10 microg of PDGF had been implanted. In sites treated with 10 microg of PDGF, the area of new bone was decreased and the area of bone marrow was reduced at twenty-eight and fifty-six days. PDGF also appeared to retard resorption of demineralized bone matrix in a dose-dependent manner. Platelet-rich plasma reduced osteoinduction by human demineralized bone matrix that had high osteoinductive activity and had no effect on osteoinduction by demineralized bone matrix with low activity. CONCLUSIONS: PDGF inhibits, in a dose-dependent manner, intramuscular osteoinduction and chondrogenesis by demineralized bone matrix in immunocompromised mice. Platelet-rich plasma also reduces the osteoinductivity of active demineralized bone matrix.

Analysis of Variance↗
PubMed2005

The CO2 laser for excisional biopsies of oral lesions: a case series study.

During a period of 12 months, 139 patients with 164 intraoral pathologic lesions were treated with a CO2 laser. Intra- and postoperative complications and the method of pain control during and after surgery were recorded. The diagnostic evaluability of the 133 soft tissue biopsy specimens sent for histopathologic analysis was examined, and the clinical and histopathologic diagnoses were compared. Nine intra- and six postoperative complications occurred. Pain control during CO2 laser surgery could be performed with a topical anesthetic in almost one third of the lesions; in the other 111 lesions, a local anesthetic had to be applied. For pain relief after the operation, 101 patients (72.7%) used only an adhesive wound paste, without any additional oral analgesic. The thermal damage from the CO2 laser on the borders of the biopsy specimens never interfered with the pathologist's establishment of a firm diagnosis. The CO2 laser is an appropriate instrument for excisional biopsies of oral soft tissue lesions. Intra- and postoperative complications were minimal, pain relief during and after surgery could be achieved in many cases through topical anesthetics, and incisional or excisional biospsies caused no diagnostic problems because of collateral thermal damage of the specimen from the laser.

Administration, Topical↗
PubMed2004

Initial implant position determines the magnitude of crestal bone remodeling.

BACKGROUND: The ability to predict the amount of bone remodeling around implants is important for a stable and predictable esthetic result. The purpose of this study was to investigate the amount of radiographic bone remodeling that occurs over time using a one-piece implant system. METHODS: Twenty-seven patients receiving implants in the maxilla and 15 receiving implants in the mandible were included in the study. All implants were placed with a non-submerged surgical technique with varying locations of the rough-smooth border with respect to the alveolar crest. Clinical exams and radiographs were taken on the day of implant placement, at 6 months, and annually up to 5 years. Linear measurements from digitized radiographs were made from the implant shoulder to the first bone-to-implant contact at all time points. RESULTS: A significant amount of bone remodeling compared to baseline occurred for all implants at the 6-month follow-up visit (1.10 mm), with the remaining time points showing virtually no change (0.1 mm). A relationship was found between the amount of bone remodeling and the location of the rough-smooth border with respect to the alveolar crest. Those implants with the rough-smooth border surgically placed below the crest had, on average, a greater amount of remodeling at 6 months (average 1.72 mm) than implants with the rough-smooth border placed at or near the crest (average 0.68 mm). In both situations, this remodeling: 1) occurred early (within 6 months), 2) reached a similar level, and 3) remained virtually unchanged up through 60 months (0.05 mm). CONCLUSIONS: A physiologic dimension appears to exist between the bone and the implant-crown interface around one-piece implants that is established early and maintained over time. These results are significant because they demonstrate in patients that the magnitude of initial bone remodeling around these one-piece dental implants is dependent on the positioning of the rough-smooth border of the implant in an apico-coronal dimension. Furthermore, the dimension, from the crown-implant interface to the first bone-to-implant contact, is consistent with the formation of a biologic width similar to that found around the natural dentition.

Alveolar Bone Loss↗
PubMed2004

Clinical and histologic evaluation of anorganic bovine bone collagen with or without a collagen barrier.

This study evaluated an anorganic bovine-derived xenograft (Bio-Oss Collagen) in the treatment of human periodontal defects. Four patients with intrabony defects on teeth that were treatment planned for extraction were enrolled in the study. Presurgical measurements of probing depth, attachment level, and recession were recorded. The surgical procedure consisted of flap reflection, debridement of the osseous defects and root surface, placement of a notch through calculus into the root surface, topical application of a tetracycline paste to the root surface, grafting with Bio-Oss Collagen, and flap closure. Three of the eight defects examined received a resorbable collagen barrier (Bio-Gide) in addition to the bone graft. Patients were seen every 2 weeks for plaque control and review of oral hygiene measures. Six months postsurgery, clinical parameters were rerecorded prior to en bloc resection of teeth and adjacent graft sites. The majority of sites showed a favorable clinical response with respect to probing depth reduction and clinical attachment gain. Histologic analysis demonstrated new bone, cementum, and periodontal ligament coronal to the reference notch in two of the eight specimens. Two sites demonstrated new attachment, and four showed a long junctional epithelium. Periodontal regeneration is possible following a bone-replacement graft of Bio-Oss Collagen.

Absorbable Implants↗
PubMed2003

Evaluation of enamel matrix derivative as an adjunct to non-surgical periodontal therapy.

OBJECTIVES: The aim of this study was to evaluate the adjunctive use of enamel matrix derivative (EMD) on periodontal healing following nonsurgical periodontal therapy (scaling and root planing - SRP). MATERIAL AND METHODS: The study was performed as an intraindividual, longitudinal trial of 3 months duration with a double-blinded, split-mouth, controlled, and randomized design. Twenty-two patients with moderate to severe chronic periodontitis were enrolled in the study. In each patient, two sites with pocket depths >/=5 mm and with radiographic angular bone defects >3 mm were selected. Baseline examination included measurement of probing pocket depth (PPD) and clinical attachment levels (CAL). The presence or absence of plaque and bleeding on probing at selected sites was also recorded. Following initial examination, full-mouth SRP was performed. Study sites were then treated with 24% EDTA for 2 min, followed by thorough irrigation with sterile saline. The sites were then randomized. The experimental site received subgingival application of enamel matrix derivative (Emdogain, BIORA AB, Malmo, Sweden). The control site received no additional treatment. At 3 months, all sites were re-examined. The response to therapy in experimental and control sites was evaluated, using change in probing depth and CAL as the primary outcome variables. Statistical analysis (paired t-tests) was used to compare response to treatment in control versus experimental sites. RESULTS: Statistically significant changes in PPD and CAL were seen in both treatment groups from baseline to 3 months. The mean PPD reduction was 2.3+/-0.5 mm for control sites and 2.0+/-0.3 mm for experimental sites. The mean CAL gain was 1.8+/-0.4 mm for control sites, and 1.4+/-0.3 mm for experimental sites. Statistical analysis, however, revealed no significant difference in PPD reduction or CAL gain between experimental and control groups (p>0.4). In addition, no difference was found between treatment groups in bleeding or plaque indices at 3 months. CONCLUSION: The findings from the present study do not support the use of EMD during routine, nonsurgical debridement of periodontal pockets as measured 3 months post SRP.

Adult↗